NUCLEO-F030R8 Default ADC Value 1.65V(2035)

[Proteus]

Hello,

When I activate ADC channel I'm getting 2035 value without any connection from ADC channels, I changed several channel

  HAL_ADC_Start(&hadc);
    HAL_ADC_PollForConversion(&hadc, HAL_MAX_DELAY);
    raw = HAL_ADC_GetValue(&hadc);
		  // Convert to string and print
    sprintf(msg, "%hu\r\n", raw);
    HAL_UART_Transmit(&huart2, (uint8_t*)msg, strlen(msg), HAL_MAX_DELAY);

[waclawek.jan]

That is OK, unconnected ADC input doesn't mean there is 0V on it.

Connect input voltage. Observe required impedance of the voltage source versus sample time, see datasheet.

JW

[Proteus]

I thought there is fail on MCU after I tried same code on F4Disco Board when ADC unconnect I got 0 value

Do you mean float voltage ?

Thanks,

[Proteus]

I pulled down ADC channel with 10K resistor , there is no affect I couldn't find graph on datasheet

[Ozone]

Did you check external connections of the associated GPIO pin on the F030 Nucleo board ?

[Proteus]

Yes of course , I tried several ADC channels , When I activate channel 1,65V appear on pin

Deactivate channels are 0V

[Ozone]

> I pulled down ADC channel with 10K resistor , ...

Connect it directly to GND - if you are sure there are no other external connections.

Any pull-up/pull-down resistor should be less than the recommended ADC input impedance.

I do not trust the Cube/HAL code either.

Did you check the GPIO/ADC register settings, and the raw conversion results ?

[Proteus]

When I connect to ADC VCC or GND Im getting 4035 or 0 values

I checked ADC settings everything seems to be normal

I changed FW package version

static void MX_ADC_Init(void)
{
 
  /* USER CODE BEGIN ADC_Init 0 */
 
  /* USER CODE END ADC_Init 0 */
 
  ADC_ChannelConfTypeDef sConfig = {0};
 
  /* USER CODE BEGIN ADC_Init 1 */
 
  /* USER CODE END ADC_Init 1 */
  /** Configure the global features of the ADC (Clock, Resolution, Data Alignment and number of conversion)
  */
  hadc.Instance = ADC1;
  hadc.Init.ClockPrescaler = ADC_CLOCK_ASYNC_DIV1;
  hadc.Init.Resolution = ADC_RESOLUTION_12B;
  hadc.Init.DataAlign = ADC_DATAALIGN_RIGHT;
  hadc.Init.ScanConvMode = ADC_SCAN_DIRECTION_FORWARD;
  hadc.Init.EOCSelection = ADC_EOC_SINGLE_CONV;
  hadc.Init.LowPowerAutoWait = DISABLE;
  hadc.Init.LowPowerAutoPowerOff = DISABLE;
  hadc.Init.ContinuousConvMode = ENABLE;
  hadc.Init.DiscontinuousConvMode = DISABLE;
  hadc.Init.ExternalTrigConv = ADC_SOFTWARE_START;
  hadc.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
  hadc.Init.DMAContinuousRequests = DISABLE;
  hadc.Init.Overrun = ADC_OVR_DATA_PRESERVED;
  if (HAL_ADC_Init(&hadc) != HAL_OK)
  {
    Error_Handler();
  }
  /** Configure for the selected ADC regular channel to be converted.
  */
  sConfig.Channel = ADC_CHANNEL_0;
  sConfig.Rank = ADC_RANK_CHANNEL_NUMBER;
  sConfig.SamplingTime = ADC_SAMPLETIME_239CYCLES_5;
  if (HAL_ADC_ConfigChannel(&hadc, &sConfig) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN ADC_Init 2 */
 
  /* USER CODE END ADC_Init 2 */
 
}

Thanks,